Resolution and stuff

Resolution is (resolving power) refers to microscopes, and is the minimum distance two objects can be apart for them to appear as separate objects.
Cell Fractionation is when cells are broken up and the different organelles they contain are separated out.
The tissue being separated must be put in a solution that is cold, isotonic, and buffered. It is cold so that any enzyme activity that could damage the organelles is stopped. It is isotonic to keep the water potential equal, to stop any organelles from bursting or becoming plasmolyzed when water is osmosed in. It is buffered to maintain a constant pH.
Ultracentrifugation is the process of how the fragments (after the solution has been homogenised [chopped up]), are filtered and separated. The ultracentrifuge (machine) spins test tubes of homogenate (chopped up tissue) at high speeds. This means the heaviest organelles are forced to the bottom of the test tube, and they form a sediment. The supernatant (fluid above this bit), it removed, and spun again at a faster speed, so the next heaviest are forced to the bottom of the tube. This is carried on until all the organelles are separated, always increasing in speed.
Cold: To stop any enzymes from working that could damage the organelles. Isotonic: To keep equal water potential, to prevent organelles from becoming turgid, or plasmolyzed. Buffered: To maintain a constant pH.
1) Magnification is increasing the size or an image, whereas resolution is the minimum distance apart two objects can be for them to be seen as separate under a microscope.
2) Magnification= Image / Actual. Therefore, Magnification = 1000 / 5 = x200
3) Image= Actual x Magnification = 25 x 400000 = 10000000, convert into mm = 10mm
4) Actual = Image/Magnification = 6 / 12000 = 0.0005mm or 0.5 um or 500nm
5) To get a sample of chloroplasts from a plant cell you would have to spin it for ten minutes, but at a gravitational force in-between 1000 and 3500, so probably around 2150.
6) Magnification = 10000, Image= 20mm, therefore, actual size is 20/10000, or 0.002mm. If magnification was 1000000 and the image was 25mm the actual size would be 25/1000000, or 0.000025 mm
7) A) Nuclei. B) Lysosomes. C) Mitochondria, Lysosomes, Ribosomes. D) Ribosomes.